1977 Deere 450c Engine Lugs even in Neutral

[Airman89]

I would think that would be the case. The only caveat being with cold oil there would be more drag than with oil at operating temperature.


Dumb question, are you turning the adjustment the correct direction?

No dumb questions I really appreciate all the help. I do believe so. The terms in the tech manual are tighten or loosen, I presumed tighten is clockwise so that’s how I tried adjusting. I have quite a ways to go before bottoming out but the screw is very tight as it is and I made sure I’m not fighting the “lock tab”.

 

[Airman89]

I meant to say, tighten to remove free play or loosen to increase free play.

 

[Airman89]

Well I’m trying to figure out which port I open to install the pressure gauge.. someone said right hand side top of transmission plug but I pulled that rubber plug out and there’s no 1/4” pipe plug, it’s more like 5/8 or 1/2”. In the manual it looks like the center plug which needs a special tool to remove?

I finally got the clutch pedal adjusted to exactly 3-3/4” free travel. I just kept turning. I ended up turning probably 5 total rotations start to finish..

Here’s a picture

 

[mg2361]

 

[Airman89]

I got it and pressures seem ok but borderline too low. I’m at 160psi in reverse and 164 in H or L. Weird how Reverse lugs and has lower pressure than H and L. Should I add shims to increase pressure or should these be ok? I have zero slipping in HL or R.

Here is a video of pressures and speeds when I shift. Order of shifts that I did was H to L, then L to H, then H to R.

450c Shifts speeds and pressures

 

[Airman89]

Heres a video showing if I go from R to N to R there doesn’t seem like as much lugging of the engine until I got from H to R then it lugs hard and stays lugging hard. At one point I heard a faint “snap or click” when I was shifting and then it was smooth in reverse for the first time. Absolutely no lugging. I didn’t get that on video though. I let it run like that for a few minutes thinking maybe something would free up?

Shifting Deere 450c in Neutral

 

[mg2361]

The HLR clutch adjustment needs to be performed first. If you apply the clutch approximately a half of an inch, does the pressure rise? It should. If it does not, then the adjustment is not correct. Procedure found in the manual TM1102, section 70, page 20-6, right side of the page.

 

[Airman89]

Sorry I forgot to mention that. Yes it rises the approximate 5psi when I press the clutch 1/2”.

I removed the rubber plug but didn’t see shims just another metal plug. Do I have to unscrew that to get to it? Sorry the manual has tons of information but is just vague enough that I can’t figure a few things out.

 

[Airman89]

Could the low reverse pressure either be the reason for the lugging (partially engaged reverse or some pressure bleeding to other clutch pack)? It’s weird how after adjusting the clutch pedal and valve, for the first time, I had no lugging in reverse for a minute. It almost felt just like H or L.

 

[mg2361]

If the pressure rises 5 psi with 1/2" of travel, then it is adjusted correctly. Any issues you are having are now internal.

 

[Airman89]

The weird thing is now it will intermittently not lug while in reverse. Is there anything else to check? What about if I shim to increase to a better/high pressure? Right now reverse is out of spec.

 

[mg2361]

Increasing the pressure will not change anything. It is simple enough to try it, though. Might have a sealing ring intermittently sealing or leaking creating the change you are noting.

 

[Airman89]

Thanks for all the very helpful information! I’m going to hook the gauge back up just to verify the clutch valve adjustment then I’ll increase the pressure some and call it good until I’m ready to pull the engine and dig in.

While I’m going to be back there working on it, is it worth looking into adjusting the shift linkage/ shift valve? Is it possible for it to be far enough off to not fully engage R or disengage H completely?

 

[mg2361]

It never hurts to make sure linkages are adjusted correctly. I honestly don't recall if something like that could happen. Looking at the parts picture, I suppose it could.

 

[Diesel Dave]

While I’m going to be back there working on it, is it worth looking into adjusting the shift linkage/ shift valve? Is it possible for it to be far enough off to not fully engage R or disengage H completely?

I don’t think it is possible to be NOT fully out of H.
You need to go through N (neutral) to get to R.
The (4) detents you feel in the reverser control handle are located on an internal housing cover, see screenshot below.
.

 

[Steve Austin]

MG2361 has you in right direction with wear in sealing ring area in oil manifold.
I have encountered this many times, the reason there is more lugging sometimes than others is that there is most likely excessive end play in shaft, and this can sometimes shift sealings rings. against worn shoulder groove and seal better Pressure oil bypassing these sealing rings can also partially engage clutch packs not selected and cause excessive lugging.
These HLR units are simple but if you have never rebuilt one buy a good repair manual and follow it precisely everything hast to be right on assembly.

 

[Airman89]

After looking through the manual it’s hard to tell where in the transmission the HLR clutch oil manifold is located. Is it in a spot in the transmission where I could only get to it if I remove the engine?

 

[Steve Austin]

Is your 450C a Crawler loader or Dozer?

 

[Airman89]

Is your 450C a Crawler loader or Dozer?

It’s the crawler loader with a backhoe.

 

[Steve Austin]

Either one is a major disassemble project with loader having more obstacles. Yes engine, clutch housing, hydraulic tank and battery box assembly, dash assembly etc to give you good accessibility to components.
A good manual with disassembly instructions is needed.